Expanded sheet metal



Patented May 21, 1929.

UNITED STATES PATENT ori-fica.: e.

LoN TIRIFAHY, or oir-ARLERQI, BELGIUM.

EXPANDED SHEET METAL.

Application led A'pril 11, 1927, Serial No. 182,891, yandinlelg'iuni AprilA 20, 1926.*V

The present invention relates to the manufacture of expanded metal and it has forv its object to provide slit andribbed metal sheets that will be particularly adapted for use in armed concrete structures.L

VIn particular the invention has reference to metal sheets in which parallel seriesk of H-shaped slits are cut prior to their expansion. When expanded such sheets comprisel parallelbands of metal connected at intervals by obliqueties or strands which, in? the course of expansion, take up an inclined-position wth respect to the general plane of the sheet and finally standvon edge in the fully expanded sheet.-

While this more or less inclined position of the ties has been considered favorable in so far as itstiiens the metal it has vbeen observed that very wide meshes are thus:

formed through which cement is allowed to pass too freely so that its adherence, to` the ties is impaired andthe use of the cement.

gun is precluded.

An object of the present invention is to'v provide a form of expanded metal in which the ties are prevented from taking `up an incllned position so that, vfor av given degree of expansion, much narrower openings are formed, the portions of metal connectingv adjacent ties being pressed into the shape of hooks whereby a particularly eflicient bind-` ing of the cement is secured. V

A further object of my yinvention is to provide expanded metal provided with lon-' gitudinal ribs, wherein not only the fiat sections between the ribs,` but the ribs themselves may be slit and expanded, thus not only aording the desired stifness but providing a far better adherence of the concrete to the vribs'than. is obtainable with the usual plain ribs.

The accompanying n drawings illustrate several examples of realization of the present invention.

Figs. 1, 2, 3 Vand 4 show various arrangements of the H-shaped slits in the metal sheets prior to their expansion and Figs. 5, 6, 7 and 8 respectively `are corresponding viewsof the expanded sheets.

Figs. 9 and 10 show in plan and end view respectively anexpanded sheet having ribs with transverse projections.

Figs. 11 and 12 likewise show an expanded sheet rovided with slit and expanded ribs.

In igs. 1 to 4, the H-shaped slits are `denoted a. In Fig. 1 they alternate with single longitudinal lslits-b arranged axially of the H- shaped slits but separated therefrom at both ends by a portion of unslit metal c. When the sheet metal is expanded (Fig. `5) theseA portions 0 can be bent atjright angles to the plane ofthe sheet so as to form hook shaped projections adapted to project into the concrete. ,l Or in the course of expansion the binding portions Z can be .raised obliquely, their ends c then vbeing bent down in a direction parallel to the sheet.

As shown in Fig. 5 this form is very simsteadrof each slit bl have provided two slits d, whilein Figs. 3 and 7 theH-shaped slits a alternate with straight slits e no longer in the longitudinal lbut in the lateral direction.l

Finally Figs. 4 and 8 show the results yobtained with twol series of H-shaped slits a and a', the latterfbeing Vslightlyoffset withk respect to the former. These various forms and others which `might be obtained with different arrangements ofthe slits, makeit e.

possiblel to multiply the hooks or projections for engaging the concrete. In practice however the form illustratedin Figs. land 5 is suitable for most cases; `it answers best the requirements as regards simplicity` and strength andfpermits ofiusing particularly f strong mach inery, thus lowering the costof manufacture. Y. n Y Y,

As stated above theslits may be distributed over .longitudinal zones or bands separated by bands of plain me-tal which may be pressed so as to form ribs. These may be `plain asin some known forms of expanded metal, but it is advantageous to provide them with projections either by pressing or by slitting or otherwise.

Figs. 9 and 10 show ribs f provided at intervals with transverse projections or ridges g made by pressing inthe course of the production of the rib, either in a press or in a rolling mill, the dies of the press or the rolls of the rolling mill then being provided with suitable projections and grooves. In forming thesel ridges the metal may be stretched, sotha-t the length of the ribs is not altered. In use these ridges efficiently prevent any longitudinal slipping of the armature within the concrete.

In the example of Figs. v11 and l2, the metal bands from which the ribs are formed are cut so as to form slits h similar to those of the flat portions. .The openings thus made in the expanded metal permit of the concrete engaging into the ribs and give a perfect adherence, making any slipping impossible within the structure. This form of rib moreover vallows of -a greater expansion of the metal sheet and increases the moment of inertia of the ribbed sheet. Hooks c similar to the hooks c can be formed by bending the metal of the ribs.

The metal sheets according to the invention are preferably manufactured in two stages, first the cutting of the slits in a press that also raises the metal portions which are to form the hooks, and then the expansion in an expanding machine which may be a press or a rolling mill. In the case of ribbed sheets the expansion may advantageouslybe carried'out .in a rolling mill in which the successive pairs of rolls have grooves of increasing depth so as to gradually form ribs of the required height while at the same time exerting on the slit portions the amount of stretching required to expand the metal. A i

By reason of the shape and arrangement of the slits'made in accordance with the present invention the strains exerted on the metal in the course of the expansion vare reduced to the minimum and sudden stresses possess a greater strength per unit weight for a given degree of expansion.` lt vill further be noticed that the openings produced by the expansion of the H-shaped slits are not of excessive width owing `to the fact that they are partly filled by 'the projections@ facing each other, so that the concrete caneasily be applied on the metal by means of the cement gun. rl`he manufacture of these sheets is also more easy and more economical as the great length of the slits makes it possible to use stronger cutting tools and to increase the speed of the progress ofthe sheets through Vthe slitting machines.

It will be understood that the shapes of expanded metal and ribs described and shown in the accompanying drawings lare simply given by way of example and that they may be Varied or combined in various ways without departing from the scope of the invention.

I claim: i

l. A sheet of expanded metal having H- shaped openings formed therein and arranged n parallel relation, said sheets comprising parallel longitudinal bauds of entire metal, pairs of oblique ties connecting said bands with each other, said ties extending with their full width substantially in the same plane as said longitudinal bands, and hook-shaped portions of metal connected t0 each of said pairs of ties.

2. A sheet of expanded metal comprising` parallel longitudinal ribs and flat sections comprised betweensaid ribs, the metal form ing both said sections and said ribs having irl-shaped openings formed therein and arranged in parallel relation, said sections and said ribs comprising each parallel longitudinal bands of metal, pairs of oblique ties connecting' said bands with each other, the

Lou Trainen-rr. 

